A
bstract
Based on an integrated luminosity of 1.61 fb
−
1
e
+
e
−
collision data collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, a search for the
P
- and
CP
-violating decay
η → ...π
+
π
−
has been performed. Radiative
ϕ → ηγ
decay is exploited to access the
η
mesons. No signal is observed in the
π
+
π
−
invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be ℬ(
η → π
+
π
−
)
<
4
.
9
×
10
−
6
, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get ℬ(
η → π
+
π
−
)
<
4
.
4
×
10
−
6
at 90% confidence level.
Abstract
The Outreach Cosmic Ray Activities (OCRA) project was created in 2018 within the Italian Istituto Nazionale di Fisica Nucleare (INFN) to offer a platform for all outreach activities focusing ...on cosmic rays within the institute. OCRA now counts 22 of the institute’s divisions all over Italy as members. The project offers activities both for students and teachers. The one activity common to all local groups is the participation in the yearly International Cosmic Day, organized by DESY, inviting high school students to carry out hands-on measurements of the cosmic ray flux and learn about the related physics background. Two students from each division are then selected to participate in the annual OCRA science camp, a three-day full immersion into the life of a physicist. For both teachers and students, the OCRA website https://web.infn.it/OCRA/, offers a series of online laboratories designed both to be used by students individually but also to be offered in the classroom by teachers. A section dedicated to teachers provides ample material to help bring these laboratories to the classroom. The online materials were presented in a course for teachers in spring 2021. In addition to the national efforts, there are also local initiatives of the OCRA member groups: workshops and secondments, science competitions and the development of new detectors for outreach activities offer a multitude of possibilities for students to engage with our researchers and to explore the world of cosmic rays. This article provides an overview on all activities offered by OCRA with a particular focus on the 2022 science camp.
Abstract The Extreme Energy Events (EEE) Collaboration is fully involved in an ecological transition. The use of the standard gas mixture, C 2 H 2 F 4 + SF 6 , has stopped in favor of an alternative ...green mixture based on C 3 H 2 F 4 with the addition of He or CO 2 . The choise of these new mixtures is motivated by the significant lower Global Warming Potential (GWP) to reduce the emission of gases potentially contributing to the greenhouse effect. The EEE experiment consists of 61 muon telescopes based on Multigap Resistive Plate Chambers (MRPCs), each telescope composed of 3 chambers filled with gas. Several EEE detectors are today completely fluxed with the new ecological mixture. This contribution will report recent results about the telescope performance obtained from studies with the eco-friendly alternative mixture carried out in the last years.
The new trigger/GPS module for the EEE project Panetta, M.P.; Abbrescia, M.; Avanzini, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Volume:
936
Journal Article
Peer reviewed
Open access
The Extreme Energy Events Project is an experiment devoted to the study of the Extensive Atmospheric Showers (EAS) which consists of a network of Multigap Resistive Plate Chambers (MRPCs) muon ...telescopes distributed over a very large area ∼3times105km2. It requires a precise time synchronization to correlate the information collected from each single detector. The data acquisition system of each telescope is equipped with a trigger unit and a GPS receiver to perform precision timing of events. The Global Positioning System (GPS) unit provides the one pulse per second signal (1PPS) which is used to create a timestamp in UTC time. A novel VME trigger unit for the EEE telescopes was developed, including an embedded GPS engine for timing application. The trigger/GPS unit is presented, including some preliminary measurements of its time resolution.
•The VME trigger unit includes an engine GPS to create the timestamp in UTC time.•The absolute time of an event is built by adding both the TDCs and the GPS data.•GPS unit provides the one pulse per second signal (1PPS) to synchronize the TDCs.•The time resolution measured for the 1PPS is less then ∼5 ns.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The whole Extreme Energy Events (EEE) array is composed of 61 telescopes installed in Italian High Schools, built and operated by students and teachers, constantly supervised by researchers. The muon ...telescope of the EEE Project is made by 3 Multigap Resistive Plate Chambers (MRPC). The unconventional working sites are a unique test field for checking the robustness and the low-ageing features of the MRPC technology for particle tracking and timing purposes. The MRPCs are fluxed with a standard mixture (98% C
2
H
2
F
4
- 2% SF
6
) of greenhouse gases (GHG) phasing out of production. The EEE Collaboration is currently studying alternative mixtures environmentally and economically sustainable. The EEE Collaboration actions to reduce the Global Warming Potential (GWP) in the MRPC array of the EEE experiment are progressing.
The Extreme Energy Events (EEE) experiment consists in a network of cosmic muon tracker telescopes, each made of three Multi-gap Resistive Plate Chambers (MRPC), able to precisely measure the ...absolute muon crossing time and the muon integrated angular flux at the ground level. To investigate the MRPC telescope response and performance, a simulation tool was developed in GEMC, software package based on GEANT4 libraries. The framework was validated by comparing simulations with the EEE experimental data. Detailed description of telescope response is fundamental to carry on the physics program of the EEE project, and it could open other research avenues, such as using the telescope in combination with other detectors to perform a (muon) tomography of material surrounding the telescope. In this paper, the EEE simulation framework will be presented reporting results and discussing further applications.
The Extreme Energy Events (EEE) experiment is a project by Centro Fermi (Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”) in collaboration with INFN, CERN and MIUR, designed to ...study cosmic rays via a network of muon telescopes, based on the Multigap Resistive Plate Chambers (MRPC) technology. Due to its wide coverage over the Italian territory (more than 10° in latitude and longitude, covering more than 3x105km2), the EEE network is the largest MRPC – based system for cosmic rays detection. Each MRPC has 6 gas gaps obtained by a stack of glass plate, spaced 250μm each, and is equipped with 24 copper strips. Since its beginning, the EEE MRPCs were filled with a gas mixture of 98% of tetrafluoroethane and 2% of sulfur hexafluoride, but recent restrictions on greenhouse gases have prompted the study of their performance with new gas mixtures. To this aim, extensive tests of tetrafluoropropene and carbon dioxide or sulfur hexafluoride gas mixtures have been carried out.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
.
A search for long distance correlations between individual Extensive Air Showers (EAS) detected by pairs of MRPC telescopes of the Extreme Energy Events (EEE) network was carried out. The search ...for an anomaly in these events is the purpose of our work. A dataset obtained by all the possible 45 pairs between 10 EEE cluster sites (hosting at least two telescopes), located at relative distances between 86 and 1200km, was analyzed, corresponding to an overall period of 3968 days time exposure. To estimate the possible event excess with respect to the spurious rate, the number of coincidence events was extracted as a function of the time difference between the arrival of the showers in the two sites, from
±
10
s to the smallest time interval where events are still observed. The analysis was done taking into account both the time and orientation correlation between the showers detected by the telescope pairs. A few candidate events with unusually small time difference and angular distance were observed, with a p-value sensibly smaller than a confidence level of 0.05.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h′, with the KLOE detector at DAΦNE. We investigated ...the case of h′ lighter than U, with U decaying into a muon pair and h′ producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2mμ<mU<1000 MeV, mh′<mU.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper the first study of the upward going events detected by the telescopes of the Extreme Energy Event (EEE) project is reported. The EEE project consists of a detector array of Multigap ...Resistive Plate Chambers located at selected sites on the Italian territory. During autumn 2014 the first coordinated data taking period took place and around one billion candidate tracks were collected. Among them, of particular interest is the sample of particles which cross the telescopes from below. The results obtained demonstrate that the EEE telescopes can distinguish the electrons produced as decay products of cosmic muons stopped in the ground, or in the last chamber of the telescopes themselves, confirming the excellent performance of the system for the investigation of intriguing cosmic phenomena.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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